当我在仪表板中创建实例时，出现错误：
未找到有效的主机。没有足够的主机可用。
在/var/log/nova/nova-conductor.log文件中，有日志：
2017-08-05 00:22:29.046 3834 WARNING nova.scheduler.utils [req-89c159c7-b40a-43eb-8f0d-9306eb73e83a 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] Failed to compute_task_build_instances: No valid host was found. There are not enough hosts available.
Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 199, in inner
return func(*args, **kwargs)
File "/usr/lib/python2.7/site-packages/nova/scheduler/manager.py", line 104, in select_destinations
dests = self.driver.select_destinations(ctxt, spec_obj)
File "/usr/lib/python2.7/site-packages/nova/scheduler/filter_scheduler.py", line 74, in select_destinations
raise exception.NoValidHost(reason=reason)
NoValidHost: No valid host was found. There are not enough hosts available.
2017-08-05 00:22:29.048 3834 WARNING nova.scheduler.utils [req-89c159c7-b40a-43eb-8f0d-9306eb73e83a 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] [instance: 2011e343-c8fc-4ed0-8148-b0d2b5ba37c3] Setting instance to ERROR state.
2017-08-05 00:22:30.785 3834 WARNING oslo_config.cfg [req-89c159c7-b40a-43eb-8f0d-9306eb73e83a 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] Option "auth_plugin" from group "neutron" is deprecated. Use option "auth_type" from group "neutron".
我搜索了SO，找到了相关的帖子：Openstack-Devstack: Can't create instance, There are not enough hosts available
我检查了mysql中的free_ram_mb：
MariaDB [nova]> select * from compute_nodes \G;
*************************** 1. row ***************************
created_at: 2017-08-04 12:44:26
updated_at: 2017-08-04 13:51:35
deleted_at: NULL
id: 4
service_id: NULL
vcpus: 8
memory_mb: 7808
local_gb: 19
vcpus_used: 0
memory_mb_used: 512
local_gb_used: 0
hypervisor_type: QEMU
hypervisor_version: 1005003
cpu_info: {"vendor": "Intel", "model": "Broadwell", "arch": "x86_64", "features": ["smap", "avx", "clflush", "sep", "rtm", "vme", "invpcid", "msr", "fsgsbase", "xsave", "pge", "erms", "hle", "cmov", "tsc", "smep", "pcid", "pat", "lm", "abm", "adx", "3dnowprefetch", "nx", "fxsr", "syscall", "sse4.1", "pae", "sse4.2", "pclmuldq", "fma", "tsc-deadline", "mmx", "osxsave", "cx8", "mce", "de", "rdtscp", "ht", "pse", "lahf_lm", "rdseed", "popcnt", "mca", "pdpe1gb", "apic", "sse", "f16c", "ds", "invtsc", "pni", "aes", "avx2", "sse2", "ss", "hypervisor", "bmi1", "bmi2", "ssse3", "fpu", "cx16", "pse36", "mtrr", "movbe", "rdrand", "x2apic"], "topology": {"cores": 2, "cells": 1, "threads": 1, "sockets": 4}}
disk_available_least: 18
free_ram_mb: 7296
free_disk_gb: 19
current_workload: 0
running_vms: 0
hypervisor_hostname: ha-node1
deleted: 0
host_ip: 192.168.8.101
supported_instances: [["i686", "qemu", "hvm"], ["x86_64", "qemu", "hvm"]]
pci_stats: {"nova_object.version": "1.1", "nova_object.changes": ["objects"], "nova_object.name": "PciDevicePoolList", "nova_object.data": {"objects": []}, "nova_object.namespace": "nova"}
metrics: []
extra_resources: NULL
stats: {}
numa_topology: NULL
host: ha-node1
ram_allocation_ratio: 3
cpu_allocation_ratio: 16
uuid: 9113940b-7ec9-462d-af06-6988dbb6b6cf
disk_allocation_ratio: 1
*************************** 2. row ***************************
created_at: 2017-08-04 12:44:34
updated_at: 2017-08-04 13:50:47
deleted_at: NULL
id: 6
service_id: NULL
vcpus: 8
memory_mb: 7808
local_gb: 19
vcpus_used: 0
memory_mb_used: 512
local_gb_used: 0
hypervisor_type: QEMU
hypervisor_version: 1005003
cpu_info: {"vendor": "Intel", "model": "Broadwell", "arch": "x86_64", "features": ["smap", "avx", "clflush", "sep", "rtm", "vme", "invpcid", "msr", "fsgsbase", "xsave", "pge", "erms", "hle", "cmov", "tsc", "smep", "pcid", "pat", "lm", "abm", "adx", "3dnowprefetch", "nx", "fxsr", "syscall", "sse4.1", "pae", "sse4.2", "pclmuldq", "fma", "tsc-deadline", "mmx", "osxsave", "cx8", "mce", "de", "rdtscp", "ht", "pse", "lahf_lm", "rdseed", "popcnt", "mca", "pdpe1gb", "apic", "sse", "f16c", "ds", "invtsc", "pni", "aes", "avx2", "sse2", "ss", "hypervisor", "bmi1", "bmi2", "ssse3", "fpu", "cx16", "pse36", "mtrr", "movbe", "rdrand", "x2apic"], "topology": {"cores": 2, "cells": 1, "threads": 1, "sockets": 4}}
disk_available_least: 18
free_ram_mb: 7296
free_disk_gb: 19
current_workload: 0
running_vms: 0
hypervisor_hostname: ha-node2
deleted: 0
host_ip: 192.168.8.102
supported_instances: [["i686", "qemu", "hvm"], ["x86_64", "qemu", "hvm"]]
pci_stats: {"nova_object.version": "1.1", "nova_object.changes": ["objects"], "nova_object.name": "PciDevicePoolList", "nova_object.data": {"objects": []}, "nova_object.namespace": "nova"}
metrics: []
extra_resources: NULL
stats: {}
numa_topology: NULL
host: ha-node2
ram_allocation_ratio: 3
cpu_allocation_ratio: 16
uuid: 32b574df-52ac-43dc-87f8-353350449076
disk_allocation_ratio: 1
2 rows in set (0.00 sec)
您看到free_ram_mb: 7296，我只是想创建一个512 mb虚拟机，但失败了。
修改-1
nova服务全部上线：
[root@ha-node1 ~]# nova service-list
+----+------------------+----------+----------+---------+-------+----------------------------+-----------------+
| Id | Binary | Host | Zone | Status | State | Updated_at | Disabled Reason |
+----+------------------+----------+----------+---------+-------+----------------------------+-----------------+
| 2 | nova-consoleauth | ha-node3 | internal | enabled | up | 2017-08-05T14:20:25.000000 | - |
| 5 | nova-conductor | ha-node3 | internal | enabled | up | 2017-08-05T14:20:29.000000 | - |
| 7 | nova-cert | ha-node3 | internal | enabled | up | 2017-08-05T14:20:23.000000 | - |
| 15 | nova-scheduler | ha-node3 | internal | enabled | up | 2017-08-05T14:20:20.000000 | - |
| 22 | nova-cert | ha-node1 | internal | enabled | up | 2017-08-05T14:20:26.000000 | - |
| 29 | nova-conductor | ha-node1 | internal | enabled | up | 2017-08-05T14:20:22.000000 | - |
| 32 | nova-consoleauth | ha-node1 | internal | enabled | up | 2017-08-05T14:20:29.000000 | - |
| 33 | nova-consoleauth | ha-node2 | internal | enabled | up | 2017-08-05T14:20:29.000000 | - |
| 36 | nova-scheduler | ha-node1 | internal | enabled | up | 2017-08-05T14:20:30.000000 | - |
| 40 | nova-conductor | ha-node2 | internal | enabled | up | 2017-08-05T14:20:26.000000 | - |
| 44 | nova-cert | ha-node2 | internal | enabled | up | 2017-08-05T14:20:27.000000 | - |
| 46 | nova-scheduler | ha-node2 | internal | enabled | up | 2017-08-05T14:20:28.000000 | - |
| 49 | nova-compute | ha-node2 | nova | enabled | up | 2017-08-05T14:19:35.000000 | - |
| 53 | nova-compute | ha-node1 | nova | enabled | up | 2017-08-05T14:20:05.000000 | - |
+----+------------------+----------+----------+---------+-------+----------------------------+-----------------+
新星名单：
[root@ha-node1 ~]# nova list
+--------------------------------------+------+--------+------------+-------------+----------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+--------+------------+-------------+----------+
| 20193e58-2c5b-44c6-a98f-a44e2001934f | vm1 | ERROR | - | NOSTATE | |
新星表演实例：
[root@ha-node1 ~]# nova show 20193e58-2c5b-44c6-a98f-a44e2001934f
+--------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Property | Value |
+--------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | AUTO |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | - |
| OS-EXT-SRV-ATTR:hostname | vm1 |
| OS-EXT-SRV-ATTR:hypervisor_hostname | - |
| OS-EXT-SRV-ATTR:instance_name | instance-00000003 |
| OS-EXT-SRV-ATTR:kernel_id | |
| OS-EXT-SRV-ATTR:launch_index | 0 |
| OS-EXT-SRV-ATTR:ramdisk_id | |
| OS-EXT-SRV-ATTR:reservation_id | r-jct8kkcq |
| OS-EXT-SRV-ATTR:root_device_name | /dev/vda |
| OS-EXT-SRV-ATTR:user_data | - |
| OS-EXT-STS:power_state | 0 |
| OS-EXT-STS:task_state | - |
| OS-EXT-STS:vm_state | error |
| OS-SRV-USG:launched_at | - |
| OS-SRV-USG:terminated_at | - |
| accessIPv4 | |
| accessIPv6 | |
| config_drive | |
| created | 2017-08-05T14:17:54Z |
| description | vm1 |
| fault | {"message": "No valid host was found. There are not enough hosts available.", "code": 500, "details": " File \"/usr/lib/python2.7/site-packages/nova/conductor/manager.py\", line 496, in build_instances |
| | context, request_spec, filter_properties) |
| | File \"/usr/lib/python2.7/site-packages/nova/conductor/manager.py\", line 567, in _schedule_instances |
| | hosts = self.scheduler_client.select_destinations(context, spec_obj) |
| | File \"/usr/lib/python2.7/site-packages/nova/scheduler/utils.py\", line 370, in wrapped |
| | return func(*args, **kwargs) |
| | File \"/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py\", line 51, in select_destinations |
| | return self.queryclient.select_destinations(context, spec_obj) |
| | File \"/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py\", line 37, in __run_method |
| | return getattr(self.instance, __name)(*args, **kwargs) |
| | File \"/usr/lib/python2.7/site-packages/nova/scheduler/client/query.py\", line 32, in select_destinations |
| | return self.scheduler_rpcapi.select_destinations(context, spec_obj) |
| | File \"/usr/lib/python2.7/site-packages/nova/scheduler/rpcapi.py\", line 126, in select_destinations |
| | return cctxt.call(ctxt, 'select_destinations', **msg_args) |
| | File \"/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py\", line 169, in call |
| | retry=self.retry) |
| | File \"/usr/lib/python2.7/site-packages/oslo_messaging/transport.py\", line 97, in _send |
| | timeout=timeout, retry=retry) |
| | File \"/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py\", line 464, in send |
| | retry=retry) |
| | File \"/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py\", line 455, in _send |
| | raise result |
| | ", "created": "2017-08-05T14:18:14Z"} |
| flavor | m1.tiny (1) |
| hostId | |
| host_status | |
| id | 20193e58-2c5b-44c6-a98f-a44e2001934f |
| image | cirros-0.3.4-x86_64 (202778cd-6b32-4486-9444-c167089d9082) |
| key_name | - |
| locked | False |
| metadata | {} |
| name | vm1 |
| os-extended-volumes:volumes_attached | [] |
| status | ERROR |
| tags | [] |
| tenant_id | 0d5998f2f7ec4c4892a32e06bafb19df |
| updated | 2017-08-05T14:18:16Z |
| user_id | 2a5fa182fb1b459980db09cd1572850e |
+--------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
修改-2
nova-compute.log有用信息中的/var/log/nova/：
......
2017-08-05 22:17:42.669 103174 INFO nova.compute.resource_tracker [req-60a062ce-4b3d-4cb7-863e-2f9bba0bc6ec - - - - -] Compute_service record updated for ha-node1:ha-node1
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [req-7dded91f-7497-4d20-ba89-69f867a2a8fb 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] Instance failed to spawn
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] Traceback (most recent call last):
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2078, in _build_resources
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] yield resources
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1920, in _build_and_run_instance
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] block_device_info=block_device_info)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2584, in spawn
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] admin_pass=admin_password)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2959, in _create_image
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] fileutils.ensure_tree(libvirt_utils.get_instance_path(instance))
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] File "/usr/lib/python2.7/site-packages/oslo_utils/fileutils.py", line 40, in ensure_tree
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] os.makedirs(path, mode)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] File "/usr/lib64/python2.7/os.py", line 157, in makedirs
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] mkdir(name, mode)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] OSError: [Errno 13] Permission denied: '/var/lib/nova/instances/20193e58-2c5b-44c6-a98f-a44e2001934f'
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]
2017-08-05 22:18:11.563 103174 INFO nova.compute.manager [req-7dded91f-7497-4d20-ba89-69f867a2a8fb 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] Terminating instance
....
答案 0 :(得分：0)
首先，您需要检查＆＃34; nova service-list＆＃34;的输出？或＆＃34; openstack计算服务列表＆＃34;。它应该显示至少一个'nova-compute＆＃39;国家服务为＆＃34; Up＆＃34;和状态为＆＃39;已启用＆＃39;。
如果上述情况正常，则计算节点与调度程序正常通信。如果没有，那么您需要检查nova-scheduler日志。
nova-scheduler有一系列过滤器，如内存过滤器，CPU过滤器，聚合过滤器，它根据您选择的风格应用于过滤器主机。即如果您选择具有16GB RAM的风格，则调度程序将过滤（内存过滤器）具有可用内存的计算主机。完成所有过滤后，调度程序将尝试在已过滤的主机上启动实例，如果失败则会尝试其他主机。默认尝试次数为3.所有这些都可以在调度程序日志中看到。这会让你清楚地知道出了什么问题。
另外你需要查看“nova show＆＃39;输出。如果您可以看到计算主机存在于＆＃34; OS-EXT-SRV-ATTR：hypervisor_hostname＆＃34; ，然后我们可以理解调度程序成功地分配了计算主机，并且计算主机出了问题。在这种情况下，您需要检查该虚拟机管理程序的nova-compute日志。
答案 1 :(得分：0)
最后我发现我将/var/lib/nova/挂载到nfs目录/mnt/sdb/var/lib/nova/，但/mnt/sdb/var/lib/nova/权限是root:root，所以我更改为nova:nova（同样到/var/lib/nova/）。
命令：
chown -R nova:nova nova
答案 2 :(得分：0)
启用debug mode以获取详细日志。
在这些文件中设置debug = True：
Restart重新配置的服务
尝试再次创建实例并检查日志。
查看nova-scheduler.log文件并尝试找到如下行：
.. INFO nova.filters [req-..] Filter DiskFilter returned 0 hosts
此行上方应为DEBUG日志，其中包含Filters详细信息，例如：
.. DEBUG nova.filters [req-..] Filter RetryFilter returned 1 host(s) get_filtered_objects /usr/lib/python2.7/site-packages/nova/filters.py:104
.. DEBUG nova.filters [req-..] Filter AvailabilityZoneFilter returned 1 host(s) get_filtered_objects /usr/lib/python2.7/site-packages/nova/filters.py:104
.. DEBUG nova.filters [req-..] Filter RamFilter returned 1 host(s) get_filtered_objects /usr/lib/python2.7/site-packages/nova/filters.py:104
.. DEBUG nova.filters [req-..] (...) ram: 37107MB disk: 11264MB io_ops: 0 instances: 4 does not have 17408 MB usable disk, it only has 11264.0 MB usable disk. host_passes /usr/lib/python2.7/site-packages/nova/scheduler/filters/disk_filter.py:70
OpenStack允许您在计算节点上过度使用CPU和RAM。这允许您以降低实例性能为代价增加在云上运行的实例数。 Compute服务默认使用以下比率：
- CPU分配比例：16：1
- RAM分配比例：1.5：1
请阅读documentation以获取更多信息。
您可以使用nova.conf更改分配比例：
cpu_allocation_ratio ram_allocation_ratio disk_allocation_ratio 答案 3 :(得分：0)
在所有计算节点中编辑/etc/nova/nova.conf并根据您的应用程序要求进行修改。
cpu_allocation_ratio = 2.0
（物理核心的两倍可以用于总实例）
ram_allocation_ratio = 2.0
（总内存的两倍可以用于总实例数
在所有计算节点中重新启动nova和nova-scheduler
systemctl restart openstack-nova-*
systemctl restart openstack-nova-scheduler.service